Method of producing fullness in yarns



Dec. 24, 1935.

G. M. PEARSALL METHOD OF PRODUCING FULLNESS IN YARNS Filed July 30, 1954 j Patented Dee. 24,1935

I Georgelilartinl'earsaihlawtuehefill. Application July so, 1934, Serial NQJSIAS'I 3 Claims. (01. lie-49$ This. inventionrelates to .the production of v yarns, particularly of animal origin, having the -ishing processes they will produce alooser yarnesses mentioned brings about a condition where appearance of fullness because the fibres are opened up. K

The principal object of the invention is to treat thefibressoastoopen themupso that after spinning and subjecting the yarn to normal fin,-

than could otherwise be obtained from the same fibres. 'The invention applies chiefly to animal fibres which are straight or have a natural crimp but it is applicable also to vegetable fibres and artificial fibres which are straight naturally but a sizing has to be used in that case.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawing in which Fig. 1 represents the original fibres;

Fig. 2 represents the same fibres curled and set and in conformity, and

Fig. 3 represents the same-fibres redrafted and in a state of non-conformity. v

For many years yarns containing animal fibres have been set" and curled with heat and moisture, by definite and well established processes. In the well established process, for curling yarns the fibres always maintain their relative positions asthey took them upon being spun into the yarn o i ally. 71 w I In the suggested new process, animal fibres which have been artificially curled or crimped are displaced by redrafting'and spinning. This produces a yarn which opens up and becomes fuller in appearance as the result of certain finishing processes upon skeins or upon fabrics in which these yarns may be used.

The underlying theory is that animal fibres are straightened and paralleled in the spinning process but tend to rearrange themselves in certain finishing processes and to take a form dictated by their original nature, or in the new process by an artificially induced nature. Animal fibres have a crimpy and curly nature, depending upon the type of the fibre, as to degree. Let us take the case of a yarn made from a, fine wool, which is very crimpy in nature. When this is made into a fabric it will shorten and full up in the finishing processes such as fulling, washing, dyeing, or steaming. In the natural state the wool fibres were crimpy and curly. In the manufacturing of the yarn the. crimpiness was partially removed by the drafting and spinning processw and the twistof the yarn served to keep. the natural crimps and curls straightened out. The effect of moisture and heat in the finishing procthe crimpy nature of the fibres asserts itself and individual fibres shorten in length and take up more space at right angles to the long axis. This is believed to explain why fabrics shrink in length and width and increase in thickness.

The new process of drafting fibres which have been previously set" by heat and moisture makes it possible to obtain from low quality animal fibres 6 (without much natural crimp or curl) a yarn which will show greater loftiness as the result of finishing than would have been possible with the untreated fibres of the same material. This proposed process may be used to produce the apl0 pearance of fullness in animal fibres, say, luster wools and/or mohair yarns used alone or in conjunction with rayon in the manufacture ofastrachan yarns. This process also makes it possible to use wools of lower quality to produce a 15 knitting yarn of open and full appearancesimilar to that which would'require a higher quality of untreated fibres.

The drawing indicates "roughly how the treatment and re-drafting of animal fibres renders ,0 possible the production of a yarn which will open up under certain finishing processes to a far greater degree than would the same yarn made of untreated fibres.

The process is fundamentally one to give the Z5 fibre a crimp} and curly nature which will assert itself under conditions which the textile industry recognizes as necessary to producing fullness of fabric or yarn appearance in naturally crimpy and curly wool. The recognized theories 'of pro- 30 ducing a lofty yarn apply to the yarns made by the new process herein discussed. The process aims to produce the desired crimpiness and curlines artificially, .whereas the industry has heretofore' been dependent upon nature to'produce the crimp and curl .on the sheeps back, taking the fibres to use as it found them.

At present there are at least two possible methods for producing the treated fibres commercially. The fibres as shown in Fig. 1 may be treated in the form of roving, tops, or yarn. It seem, however, that treating the yarn is too expensive and treating in top form might not impart enough character to the. fibre. It will be assumed that the roving stage is the most suitable place for setting fibres to produce a particular effect, and the process proceeds as follows: The roving is twisted to the desired degree'and in the desired direction. The desired degree of twist for setting is usually more than the normal roving twist called for in normal manufacturing processes. The greater the roving twist the greater the twist of the individual fibre, the more character it will have and the greater will be its effect upon the properties of the resulting yarn made by the new process. The roving twist direction may be the same as that of the yarn to be made, it'may be of opposite direction, or it may be made by mixing various ends of rovings 'of both twist directions. Yarn m'ade-fromroving .0

which has been set in the same directions as thatofthefinishedyarnwillhaveatendency toproduceatubularyarnwhenfinishedinthe fabric or skein. By setting the roving twist in the opposite direction from that desired in the finished yarn the artificial nature of the fibres tends to eliminate the tubular appearance noted above. This latter is in general a more desirable effect.

Theroving may be spun on hollow perforated bobbins to fit into Franklin processor Thiess process dyeing machines, and treated with boiling water in said machine for a time which practice has shown to be sumcient for producing a satisfactory curling. This method of handling has the advantage of permitting the yarn to be dyed at the same time that it is being set. The time of treatment and thetemperature of the dye liquor is usually satisfactory and equivalent to the heating or boiling in water which would otherwise be required. The roving is then dried in the usual manner and said roving is then again put through a twister (or rover properly used as twister) to remove twist to the desired point. This condition is shown in Fig. 2. The roving then is drafted and spun into yarn or into finer rovings preliminary to being spun into yarn of the desired count (as shown in Fig. 3). It will be seen that the final drafting displaces the crimped fibres longitudinally from each other, thus forcing them to separate laterally and produce the full appearance shown in-Fig. 3. This full appearance does not appear until the yarn has been subjected to the finishing processes, as previously mentioned. I

An alternate method is to put the specially twisted roving into skein form as it is prepared for setting. It may then be handled either loosely or on. forms to be placed into a tank for boiling. The use of forms has the advantage that they may be used to speed drying by centrifuging and later may be used as dressing spools to feed the various spindles when the twist is being removed to a degree to permit drafting for respinning. Theexpense is reducedabout one half by the use of this method.

If the animal fibres used have an appreciable amount of natural crimp and curl it is advantageous to remove the tension in the longitudinal direction of the yarn by handling the skeins loose or fitting loosely on a form. The natural crimp and curlwill then assert themselves and cause the fibres to tend to assume'their natural form while the fibre is being plasticized to set in the spiral form of the twisted roving. If the yarn is treated under tension any crimp and curl which it had originally is largely lost by preventing the longitudinal yarn shrinkage which must accompany the adjustment of spun fibres to their natural condition of crimp and curl.

After the roving has been boiled in skein form for the required time, which increases with the amount of roving twist, it is removed from the tank and usually placed in a hot air drier where the temperature is held at a temperature preferablyover 160 1''. until it is dry. The roving is then ready to have'the excess twist removed.

Then it is subjected to further draftings and spinnings to produce the desired yarn.

Still another method for introducing a suitable curliness to the fibre is as follows: Two or more rovings with the normal amount of twist required under'usual manufacturing conditions, may be twisted together. The ply twist should be in the same direction as the roving twist.

This is known as "twist on twist". These plied rovings thus produced may be put into skein form and set according to the usual process. The fibres are thereby given twists corresponding to that in the individual strand combined with the a twist of the cable. They are opened and redrafted afterwards.

While the foregoing methods of producing setinthefibresisbelievedtobebest.theyare not the only successful methods that can be used. 10 The roving skeins are sprayed in loose form' followed by the hot drying process mentioned above and drafting.

A degree of satisfaction can be obtained from steaming the yarn for about half an hour, prefl5 erably under pressure fq setting, after which the yarn is drafted as b! ore after cooling and drying if found to be in too damp condition after steaming.

Primarily, however, the method for obtaining 20 permanent set in the fibre is not the important point, as this field is already widely established in the industry. The efl'ect produced by the redrafting of fibres is the main feature, thereby ofisetting them from their neighbors'so that 25 their artificially induced nature may produce an opening up of the fibres in the yarns, upon'application of certain finishing processes to the'yarn or to fabrics in which the yarns are used.

Some sort of sizing material, such as water'- 30 glass, resin, or'other water insoluble materials, can be used to protect and hold the fibres in an artificially crimped and curled condition. This of course furnishes another method of treating the fibres prior to a drafting'process to displace 35 them from positions of relative conformity to their neighbors. Sizing materials of a suitable nature therefore permit the application of the process to vegetable fibres or artificial fibres, which cannot be permanently set by the heat 40 and moisture process which is suitable for animal fibres. In all cases the resulting yarn has a full and open appearance when put through certain finishing processes to a degree not heretofore obtainable with fibres of the same quality. 45

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is:-

l. The process of treating roving which comprises twisting the roving to a higher degree than the normal roving twist, spinning, subjecting the roving to the action of boiling liquid, d y ng. twistingin the reverse direction to remove part of the twist imparted by the spinning, redrafting to displace the fibers longitudinally, and spin-- ning.

2. The process of treating roving comprising twisting the roving to a higher degree than the ,normal roving twist. spinning in a direction opp'osite to the first direction of the yarn to be made, boiling in a liquid dye, drying, twisting to remove part of the twist imparted by the spinning, redrafting to displace the fibers longitudinally, and spinning it into yarn. 05

3. The process of making yarn which comprises twisting the fibers to a higher degree than the normal roving twist, spinning. putting the product into loose skeins on forms, boilingin a liquid. drying in hot air at a temperature over 160' F.. twisting in the reverse direction toremove part of the twist imparted by the original spinning, redrafting to displace the fibers longitudinally, and spinning it into yarn.

anomam'rm PEARSALL. '15 

